Ok I am confused. I dont know whether to use urethane or butyl.

  From what I have learned so far there are 2 ways to replace/reseal a new windshield.  One uses urethane which comes in a container much like bathroom caulk and is squeezed onto the frame.  Urethane is the more modern material and from what the glass man said was used beginning in the 1980's.  The problem with using this on an older windshield (1971) is that it is softer than butyl and compresses  much thinner when  the glass is laid into it which causes the trim to not fit properly (gaps).

Butyl is like 2 sided tape only much thicker (1/4 inch) that is placed in the windshield channel and the windshield set on top of it.  It is used in older cars (pre 80's) and provides the appropriate thickness to be compatible with the trim surround pieces from that era.

I have seen posts that urethane is the way to go but have also seen posts about windshield trim gaps after a new WS installed and wonder if this could explain the problem on cars that orinally had butyl. I am leaning towards the the butyl tape unless there is a good reason not to use it.  It looks easier for the novice (me) to use.

Any comments?
Rgds   Neil

If the windshield was originally installed with butyl, you should use butyl for replacement. It is a soft rubber and stays soft.

The urethane hardens as it cures and does a better job of holding the windshield in place after it has cured.

From a safety standpoint, you are better off with the urethane, but if you want original, you need butyl.

It is still your choice.dwright38519.6538541667

Dwright

Thanks for the respose. Just out of curiosity, why is urethane safer?

Thanks
Neil

 

 

Urethane bonds the glass to the window frame, making it a structral part of the car.  Butyl seals the glass and holds it in place, but does not bond it.

[QUOTE=kstyer] Urethane bonds the glass to the window frame, making it a structral part of the car.  Butyl seals the glass and holds it in place, but does not bond it.[/QUOTE]

That's what I was told by a reputable glass installation company. Today's modern cars rely on the glass to help support the roof during a roll-over. Also, you will not go through a modern windshild in the case of a head-on crash. A windshield with butyl can be kicked out of the frame from the inside of the car.
You don't have a passenger side air bag, but they are designed to inflate, hit the windshield and then catch you as you come forward. You don't want the windshield to fly out when that happens.